The Nature Writers of Texas

The best nature writing from the newspaper, magazine, blog and book authors of the Lone Star State . . .

Sunday, November 25, 2007

An Explosion of Julias
by Ro Wauer

I’ve never approved of describing a sudden population increase of any animals, whether mammals, herps or bugs, as an “explosion.” It doesn’t seem appropriate. But now, with the unbelievable numbers of Julias (Heliconian iulia) that have suddenly “invaded” our Mission Valley, Texas yard, the term explosion seems most appropriate. During the second and third weeks of November, Betty and I have counted more that 200 individual Julias at one time in our yard. High estimates have reached 300. They were attracted to the numerous blooming crucitas and white bonesets (Eupatorium odoratum & E. wrightii), apparently finding these two shrub species to their liking. Fresh individual Julias seemed to appear daily, perhaps replacing those that died or wandered away.

Although the peak boneset blooms lasted only about two weeks, most of the two dozen or so crucita shrubs remained in flower for an additional five to six weeks. As the bonesets faded, the crucitas received even greater attention from Julias. And when some of the crucitas began to fade, the constantly flowering sky-flowers (Duranta erecta) and lantanas (Lantana sp.) attracted their attention.

This year (2007) is not the first time we have recorded Julias in our yard, although never before have the numbers been so great. Since keeping almost daily (except when away from home) records of our butterfly observations, starting in 1996, our first Julia sighting was on May 21, 1999. Since then Julia sightings have been sporadic and widely scattered. Our records included only one or two individuals during May, June and July, a slight increase in August, more numbers after mid-September through most of November, and none after December 12. But daily numbers never exceeded seven individuals. Until this year!

What has triggered this 2007 explosion of Julias? It must relate to the record rainfall in Victoria County. Our yard does not contain an abundance of passion vines (Passiflora sp.), Julia’s larval foodplants, although the adjacent private (nonaccessible) woodland (approx. 2 X 4 mile) undoubtedly does possess scattered Passiflora species; P. foetida, P. incarnata, P. lutea, and P. tenuiloba are all possible. The majority of Julias, because of their abundance, assumedly emerged from nearby sites. Probably our fall population also included strays from the south.

Although Julias were our lepidopteran centerpiece this fall, much greater than normal numbers of Zebra Heliconians (Heliconius charithonia) and Sickle-winged Skippers (Eantis tamenund) also were present throughout the same period. Other species recorded in larger than normal numbers included Long-tailed Skippers and Dorantes Longtail (Urbanus proteus & U. dorantes) and Ocola Skippers (Panoquina ocola). But at least three species that usually occur in good numbers during October and November, were seldom seen or did not put in an appearance at all: Lyside Sulphur (Kricogonia lyside), American Snout (Libytheana carinenta), White Peacock (Anartia jatrophae), and Common Mestra (Mestra amymone).

The amazing number of Julias provided some unusual observations. Early morning walks around the yard, before Julias became active, revealed many individuals perched alone where they apparently had been the previous evening, on various shrubs and even on the ground. The closely-related Heliconians typically gather at colonial roosts each night. We found Julias to be some of the earliest active butterflies, along with Zebras and Monarchs (Danaus plexippus). We also found that Julias seek moisture more than most species. We often found several individuals scattered on the lawn or ground after each watering, not puddling in groups, but individuals scattered about. And by mid-November, mating pairs increased significantly.

Also by mid-November, many of the “old-timers” showed their age by their fading colors. Instead of showing deep orange, their changing wings revealed a variety of patterns. Some of these were fascinating and truly unusual. Especially females, with their more mottled undersides, changed from orange to yellow. Our yard of Julias has offered a new and unexpected mosiac of patterns and colors. But then, like other indicators of the end of summer, our circus of Julias rapidly declined.

Sunday, November 18, 2007

Wintering Ruby-crowned Kinglets Are Back
by Ro Wauer

I suppose that some of the most common bird questions I hear this time of year are about ruby-crowned kinglets. What is that tiny yellowish bird? Why is it so nervous? How come, if it is a ruby-crowned kinglet, why I can’t see its ruby crown? All are good questions, and at least the first two help to identify this little songbird. It certainly is the smallest of our wintertime songbirds. In the North American bird world, only hummingbirds are smaller. And a good observer can not help but notice its extremely nervous behavior of constant movement, rapidly shifting about and moving its wings even when perched.

Ruby-crowns are fairly easy to identify because of their size and wing-flicking behavior, but also their broken whitish eye-ring, two white wing bars, and the male’s red crown patch that, unless they are agitated, is not often seen. A highly concerned individual, perhaps due to a nearby predator, usually will raise its red crown as if to frighten or warn a predator. During the breeding season, it will flash its red cap even more. But overall, wintering ruby-crown kinglets are greening-yellow birds that spend most of their time hunting tiny insects and spiders high in the canopy or shrubbery.

Although it is one of our most abundant wintertime songbirds, because of its habit of not coming to feeders or feeding on the ground, it is not as obvious as most of our other wintering songbirds. But for those of us with an “ear for the birds,” its songs and calls give it away. Its call is a husky “did-it,” and its song, although uncommon in winter, is a loud, variable “tee tee tee, tew tew tew, teedadee.” By late winter, ruby-crowns can often be heard singing partial songs, probably preparing for courtship on their breeding grounds north and west of Texas. Nesting occurs in the conifer forests of the Sierra Nevada and northward throughout boreal Canada and Alaska.

Although breeding birds rarely mingle with other songbirds, in winter they usually occur in bird parties (flocking) that may include numerous individuals of several species. Typical bird parties in South Texas may include tufted titmice, Carolina chickadees, white-eyed vireos, blue jays, various warblers, especially orange-crowns, and even a few non-passerine species such as sapsuckers and woodpeckers. Flocking birds is said to relate to the available food supply. Flocking increases feeding efficiency, although it is less important when food is super abundant. In addition, the various individuals in a bird party, utilizing slightly different habits in feeding, rarely miss the presence of a predator and are able to warn the other members.

Seeing a ruby-crowned kinglet well may require a little more attention than a quick look out of the window. Since they usually stay in or near heavy foliage where they can easily elude a predator, it usually requires a concerted effort and a pair of binoculars. But they are present throughout our area all winter, and finding and watching one of these little songbirds can help brighten the day.

Sunday, November 04, 2007

Dogs Have Been Man’s Best Friends For a Long, Long Time
by Ro Wauer

Over the years we have had a number of dogs, from strays found along the roadsides to a beagle that Betty couldn’t resist in a pet shop and carried that little pup home on an airline with everyone admiring it as it peaked out of a basket to see its strange new world. And over the years I had always believed, assumed would be more appropriate, that all North America dogs were descendents of wolves that were tamed by some hardy American Indian family. And eventually some dog breeder turned the wolf-dogs into different breeds that we see today. Well, now I find in an article in the Fall 2007 Defenders, the magazine of the Defenders of Wildlife, that tells me that my assumptions were only partly correct.

Author Jim Yuskavitch, an Oregon-based freelance writer, states that domestic dogs originated not in America, and not in Europe, but in East Asia more than 100,000 years ago. Canid bones and skulls have been found in dated archeological sites. He claims that “some genetic research supported the notion that dogs split from wolves as far back as 135,000 years ago.” He states that our North American dog ancestors probably arrived to North America from Asia via the “Bering land bridge at least 12,000 years ago.”

Yuskavitch also mentions that a Swedish scientist, who obtained DNA from more than 1000 samples of dog hairs from 654 types of dogs from around the world, found that they all came from a common ancestor: Asian wolves. All of today’s dog types, whether they are shepherds, beagles or poodles, possess similar DNA.

The article goes on to speculate how the Asian wolves were first domesticated. As might be expected, those early wolves may have hung around hunting camps where they competed with humans for food, risking death only from clubs and spears rather than guns. Like hunting camps today, some wild dogs eventually become brave enough to take food from humans and gradually were tamed. Or a wolf pup could have been found early enough, brought into camp and cared for, and it eventually became domesticated. One researcher stated that a wolf pup would have to be less than 20 days old, or it could not have been “socialized.” Over 19 days old, he claims, it will always remain a wild and potentially dangerous animal.

Raymond Coppinger, a Massachusetts biologist who has studied this issue for many years, believes that domestic dogs were commonplace in human societies by 7000 to 8000 years ago. Remains, including some wearing collars, have been found in archeological sites from that period and after.

It at first seems strange to think that our pet dogs came from ancestors that roamed the East Asian plains. But after all, they had to come from somewhere. And some of our breeds, such as some terriers, still possess some of those same wild traits. So maybe the behavior of that barking little fido comes naturally.